There are various challenges that exist with generating images that were originally captured in a variety of scenarios and environments, including low light levels, high noise, and high dynamic range (HDR) situations. The dynamic range in an imaging situation refers to the range of luminance values in the scene to be imaged. It can be expressed as the ratio of the greatest luminance value in the scene to the smallest luminance value in the scene. Most imaging systems are not capable of acquiring or capturing an HDR image with a single exposure. Thus, HDR images are typically computer-generated or generated from a combination of images captured at different times or with different exposure settings.
Once an HDR image has been created, it can be challenging to satisfactorily display the image in an electronic or printed medium. The challenge comes primarily from the lack of dynamic range in the electronic or print medium. This challenge is typically addressed with tone mapping operators (TMOs), which convert a range of luminance values in an input image into a range of luminance values that well matches the electronic or pre-print medium.
Further, there is a need to provide techniques and algorithms for improved tone mapping and for improved generation of HDR images.
It is against this background that the techniques and algorithms described herein have been developed.